Fix python3 compatibility

- basestring type doesn't exist anymore in python 3, use six.string_types
- verify.py uses __future__ module to use print as a function and is now
python 3 compliant

Change-Id: Iddc722af88ff7ec5c4d82daf8bd2dbef959f332c
diff --git a/rdoinfo/__init__.py b/rdoinfo/__init__.py
index a3b0992..408659d 100644
--- a/rdoinfo/__init__.py
+++ b/rdoinfo/__init__.py
@@ -1,11 +1,9 @@
 import copy
 import collections
+import six
 import yaml
 
 
-__version__ = '0.2'
-
-
 class RdoinfoException(Exception):
     msg_fmt = "An unknown error occurred"
 
@@ -100,7 +98,7 @@
     # substitution is very simple, no recursion
     new_pkg = copy.copy(pkg)
     for key, val in pkg.items():
-        if isinstance(val, basestring):
+        if isinstance(val, six.string_types):
             try:
                 new_pkg[key] = val % pkg
             except KeyError:
diff --git a/verify.py b/verify.py
index 402780a..4f2fc66 100755
--- a/verify.py
+++ b/verify.py
@@ -1,12 +1,13 @@
 #!/usr/bin/env python
+from __future__ import print_function
 import rdoinfo
 import yaml
 
 
 def verify(fn):
     info = rdoinfo.parse_info_file(fn)
-    print yaml.dump(info)
-    print "\n%s looks OK" % fn
+    print(yaml.dump(info))
+    print("\n%s looks OK" % fn)
 
 
 if __name__ == '__main__':